Abstract

New aminoguanidinium metal oxalate complexes with the formulae (AmgH)2[Cu(C2O4)2] and (AmgH)2[Cd(C2O4)2(H2O)2] have been synthesized and characterized. The copper compound loses aminoguanidine exothermically at 240 °C in DTA, whereas aminoguanidine is lost endothermically at 200 °C in cadmium. Both cases decompose exothermically via their respective metal oxalate intermediates to give metal oxide as the end product. It was also observed that hydrazine is lost exothermically in the hydrazinium copper oxalate hydrate. The single-crystal X-ray diffraction study of the copper complex revealed that aminoguanidinium ions are not involved in coordination but act as charge-compensating cations. It is interesting to note that both oxalates act as bidentate chelating ligands. One oxalate bridges the neighbouring copper atom through its carbonyl oxygen with a bond length of 2.561 Å to form square pyramidal geometry around the copper atom.